<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <script src="jquery-3.1.1.js"></script>
    <style>
        div{
            width: 300px;
            height: 300px;
            border: 2px solid green;
            display: flex;
            justify-content: center;
            align-items: center;
            font-size:26px;
         
        }
        img{
            max-width: 100%;
            max-height: 100%;
            
        }
  </style>
</head>
<body>
    <div><span>拖拽图片上传</span><img src="" alt=""></div>
    <button>上传</button>
    
</body>
</html>
<script>
    $(
</script>